Ion exchange extraction of metallic and non-metallic anions by control of the basicity of amine extractants

Abstract

Amine extractants useful in extracting metallic anions are modified with Lewis bases, having substantial organic solubility, such as tributyl phosphate, to improve the extraction capability of such amines. Generally, addition of Lewis bases to weakly basic amines increases the basicity of such amines.

We claim: 
     
       1. In an amine extraction process employing water insoluble amines capable of protonation to extract gold and rhenium anions from an alkaline aqueous solution, the improvement comprising conducting said extraction under substantially alkaline conditions by adding a modifier to increase the basicity of the amine extractant, said modifier being an organic soluble compound capable of sharing a pair of electrons, and said amine extractant being a primary, secondary or tertiary amine attached to an organic moiety having a minimum of six carbon atoms. 
     
     
       2. The process of claim 1 wherein the improvement further comprises the modifier being a Lewis base. 
     
     
       3. The process of claim 1 wherein the improvement further comprises the modifier being an organic chalcogenide selected from the group consisting of organic phosphorous oxides, organic phosphorous sulfides, and organic sulfur oxides. 
     
     
       4. The process of claim 3 wherein the improvement further comprises the modifier being an organic phosphorous oxide selected from the group consisting of phosphates, phosphonates, phosphinates, and phosphine oxides. 
     
     
       5. The process of claim 1 wherein the improvement further comprises the modifier having minimal water solubility. 
     
     
       6. The process of claim 1 wherein the improvement further comprises the anions being a metal complex. 
     
     
       7. The process of claim 1 wherein the improvement further comprises the extraction process being a liquid extraction process. 
     
     
       8. The process of claim 1 wherein the improvement further comprises the amine being associated with a solid substrate.